Abstract
Purpose :
Age-related macular degeneration (AMD) is a devastating eye disease affecting millions of people. One of the compounds that has been shown to contribute to AMD is the vitamin A derivative A2E (N-retinyl-N-retinylidene ethanolamine). Another compound, zeaxanthin, is a carotenoid that naturally accumulates in the retina. Supplements containing zeaxanthin as well as other carotenoids have been shown to improve vision and prevent progression of damage to advanced AMD in some studies. We wanted to see if zeaxanthin alone could protect vision loss associated with A2 in the zebrafish retina.
Methods :
Adult zebrafish were maintained using standard conditions. All experiments were approved by our university IACUC. Baseline visual acuity was measured using the optokinetic response as previously described. One eye was injected with 50 µM A2E and the other eye was injected with 0.46 ng/µl zeaxanthin and 50 µM A2E. Visual acuity was assessed at weekly intervals after the injections. Statistical analysis was done using a paired t-test.
Results :
Baseline visual acuities were consistent with previously published acuities in adult zebrafish. The average baseline acuity for the right eyes was 49 cycles/degree (c/d) and the left eyes was 47 c/d. A2E caused the visual acuity to slowly decline, whereas zeaxanthin protected the retina from the A2E damage. By the 2nd week post injection, the A2E injected eyes had a nearly 7% decline in the visual acuity on average compared to the original baseline. Zeaxanthin protected the opposite eye. Most eyes even saw an increase in visual acuity relative to baseline.
Conclusions :
Zeaxanthin protected visual acuity in zebrafish from A2E damage. Because the zebrafish retina regenerates, longitudinal studies are limited using this testing paradigm, so another model or system may be needed to study the long-term effects of these treatments.
This abstract was presented at the 2022 ARVO Annual Meeting, held in Denver, CO, May 1-4, 2022, and virtually.